Transformers also hadn't been producing much in the way of comics until the new movies. I remember when I completed my Transformer comic collection, sometime back around '98 or so. I never had to add to it until Bay began producing the new films.

This is not accurate.

You may not have been collecting/reading but there were plenty of books before the films.

Dreamwave had a very popular run from 2001 till early 2005.

And IDW picked up in mid 2005 with their first mini and have continued toi do minis, spotlights and a monthly since then.